I took a 'sick day' about 2 months ago now in order to skip my day job. Slightly different situation though, I actually let the guy that would need to cover the work know I was going to do it 1-2 weeks in advance, the reason being I was helping out the guy I do weekend work with set up for a major gig. I actually worked about 12 hours that day, though I got about half again my day jobs hourly wage for doing it, hence why I did it in the first place. I was actually going to put in for a rostered day off but they guy I work with encouraged me to just call in sick and use a sick day from my time. This was on a Thursday. So I did that came in Friday and the guy I work with took Friday off in return.

So in this case, it was a case of no harm no foul, but then I imagine the OP was more refering more to 'get out of bed and feel like having a lazy day' sort of thing.